In today's telephony and communication networks, an access tandem may provide connections between inter-exchange or long distance exchanges (IXCs) and end-office exchanges. An access tandem is typically engineered to provide trunking and other resources to handle expected call traffic loads.
Bottlenecks may arise when a sudden surge of originations occur, where each of the originations indicates a same or common desired destination accessible via a particular access tandem. All originations indicating the same or common destination must traverse the particular access tandem more or less simultaneously, or at least within a short time interval, in order to reach the common desired destination. The sudden surge may increase call traffic loads to a greater capacity than a capacity for which the particular access tandem was engineered to handle.
These scenarios may occur when the desired destination corresponds to a communications service. For example, such a scenario may occur when a television program advertises a call-in vote. Viewers may originate a large volume of calls over a short duration of time destined for the same voting communications service. Another example may be when a corporate, university, conference or trade-show hosts a conference call. Here, a plethora of attendees may call in to a conference call bridge more or less simultaneously. Yet another example of a sudden surge of originations for a common destination may occur when tickets for a popular concert go on sale.
In these and other examples, support to handle the sudden surge of originations may be limited by the available resources of the access tandem. A bottleneck may occur on an originating side of the access tandem, for instance, over the trunking resources from an originating local exchange or IXC to the access tandem. Other bottlenecks may occur on the terminating side of the access tandem, for instance, over the trunking resources from the access tandem to a local exchange where the desired destination or communication service may be accessed. Logical resources internal to the access tandem may also be limited. Trunking and other call resources may be expensive to engineer, implement and maintain, so typically, the resources are not engineered for a maximum surge scenario. Accordingly, the amount of available resources at the access tandem may be insufficient to support sudden, large load surges. Many of the calls may be blocked, resulting in inconvenience and frustration for the callers, not to mention incompletion of the desired communications service and a potential loss of revenue.